| Orthology | 
| K03914   | F2R, PAR1; coagulation factor II (thrombin) receptor |  
 | K03915   | BDKRB1; bradykinin receptor B1 |  
 | K03916   | BDKRB2; bradykinin receptor B2 |  
 | K03990   | C3; complement component 3 |  
 | K03994   | C5; complement component 5 |  
 | K04009   | C3AR1; C3a anaphylatoxin chemotactic receptor |  
 | K04010   | C5AR1, CD88; C5a anaphylatoxin chemotactic receptor 1 |  
 | K04129   | CHRM1; muscarinic acetylcholine receptor M1 |  
 | K04130   | CHRM2; muscarinic acetylcholine receptor M2 |  
 | K04131   | CHRM3; muscarinic acetylcholine receptor M3 |  
 | K04132   | CHRM4; muscarinic acetylcholine receptor M4 |  
 | K04133   | CHRM5; muscarinic acetylcholine receptor M5 |  
 | K04134   | CHRMN; muscarinic acetylcholine receptor |  
 | K04135   | ADRA1A; adrenergic receptor alpha-1A |  
 | K04136   | ADRA1B; adrenergic receptor alpha-1B |  
 | K04137   | ADRA1D; adrenergic receptor alpha-1D |  
 | K04138   | ADRA2A; adrenergic receptor alpha-2A |  
 | K04139   | ADRA2B; adrenergic receptor alpha-2B |  
 | K04140   | ADRA2C; adrenergic receptor alpha-2C |  
 | K04141   | ADRB1; adrenergic receptor beta-1 |  
 | K04142   | ADRB2; adrenergic receptor beta-2 |  
 | K04143   | ADRB3; adrenergic receptor beta-3 |  
 | K04144   | DRD1; dopamine receptor D1 |  
 | K04145   | DRD2; dopamine receptor D2 |  
 | K04146   | DRD3; dopamine receptor D3 |  
 | K04147   | DRD4; dopamine receptor D4 |  
 | K04148   | DRD1N; dopamine receptor D1-like |  
 | K04149   | HRH1; histamine receptor H1 |  
 | K04150   | HRH2; histamine receptor H2 |  
 | K04151   | HRH3; histamine receptor H3 |  
 | K04152   | HRH4; histamine receptor H4 |  
 | K04153   | HTR1; 5-hydroxytryptamine receptor 1 |  
 | K04157   | HTR2; 5-hydroxytryptamine receptor 2 |  
 | K04160   | HTR4; 5-hydroxytryptamine receptor 4 |  
 | K04161   | HTR5; 5-hydroxytryptamine receptor 5 |  
 | K04162   | HTR6; 5-hydroxytryptamine receptor 6 |  
 | K04163   | HTR7; 5-hydroxytryptamine receptor 7 |  
 | K04166   | AGTR1; angiotensin II receptor type 1 |  
 | K04167   | AGTR2; angiotensin II receptor type 2 |  
 | K04168   | NMBR; neuromedin B receptor |  
 | K04169   | GRPR; gastrin-releasing peptide receptor |  
 | K04170   | BRS3; bombesin receptor subtype-3 |  
 | K04172   | FPR1; formyl peptide receptor 1 |  
 | K04173   | FPRL; formyl peptide receptor-like |  
 | K04194   | CCKAR; cholecystokinin A receptor |  
 | K04195   | CCKBR; cholecystokinin B receptor |  
 | K04197   | EDNRA; endothelin receptor type A |  
 | K04198   | EDNRB; endothelin receptor type B |  
 | K04199   | MC1R; melanocortin 1 receptor |  
 | K04200   | MC2R; melanocortin 2 receptor |  
 | K04201   | MC3R; melanocortin 3 receptor |  
 | K04202   | MC4R; melanocortin 4 receptor |  
 | K04203   | MC5R; melanocortin 5 receptor |  
 | K04204   | NPY1R; neuropeptide Y receptor type 1 |  
 | K04205   | NPY2R; neuropeptide Y receptor type 2 |  
 | K04206   | NPY4R; neuropeptide Y receptor type 4 |  
 | K04207   | NPY5R; neuropeptide Y receptor type 5 |  
 | K04208   | NPY6R; neuropeptide Y receptor type 6 |  
 | K04210   | GPR83, GPR72; G protein-coupled receptor 83 |  
 | K04211   | NTSR1; neurotensin receptor 1 |  
 | K04212   | NTSR2; neurotensin receptor 2 |  
 | K04213   | OPRD1; delta-type opioid receptor |  
 | K04214   | OPRK1; kappa-type opioid receptor |  
 | K04215   | OPRM1; mu-type opioid receptor |  
 | K04216   | OPRL1; nociceptin receptor |  
 | K04217   | SSTR1; somatostatin receptor 1 |  
 | K04218   | SSTR2; somatostatin receptor 2 |  
 | K04219   | SSTR3; somatostatin receptor 3 |  
 | K04220   | SSTR4; somatostatin receptor 4 |  
 | K04221   | SSTR5; somatostatin receptor 5 |  
 | K04222   | TACR1; tachykinin receptor 1 |  
 | K04223   | TACR2; tachykinin receptor 2 |  
 | K04224   | TACR3; tachykinin receptor 3 |  
 | K04226   | AVPR1A; arginine vasopressin receptor 1A |  
 | K04227   | AVPR1B; arginine vasopressin receptor 1B |  
 | K04228   | AVPR2; arginine vasopressin receptor 2 |  
 | K04229   | OXTR; oxytocin receptor |  
 | K04230   | GALR1; galanin receptor 1 |  
 | K04231   | GALR2; galanin receptor 2 |  
 | K04232   | GALR3; galanin receptor 3 |  
 | K04234   | F2RL1, PAR2; coagulation factor II (thrombin) receptor-like 1 |  
 | K04235   | F2RL2, PAR3; coagulation factor II (thrombin) receptor-like 2 |  
 | K04236   | F2RL3, PAR4; coagulation factor II (thrombin) receptor-like 3 |  
 | K04238   | HCRTR1; hypocretin (orexin) receptor 1 |  
 | K04239   | HCRTR2; hypocretin (orexin) receptor 2 |  
 | K04240   | NPFFR1; neuropeptide FF receptor 1 |  
 | K04241   | UTS2R; urotensin 2 receptor |  
 | K04247   | FSHR; follicle stimulating hormone receptor |  
 | K04248   | LHCGR; lutropin-choriogonadotropic hormone receptor |  
 | K04249   | TSHR; thyrotropin receptor |  
 | K04258   | PTGER1; prostaglandin E receptor 1 |  
 | K04259   | PTGER2; prostaglandin E receptor 2 |  
 | K04260   | PTGER3; prostaglandin E receptor 3 |  
 | K04261   | PTGER4; prostaglandin E receptor 4 |  
 | K04262   | PTGFR; prostaglandin F receptor |  
 | K04263   | PTGIR; prostacyclin receptor |  
 | K04264   | TBXA2R; thromboxane A2 receptor |  
 | K04265   | ADORA1; adenosine receptor A1 |  
 | K04266   | ADORA2A, ADOR; adenosine receptor A2a |  
 | K04267   | ADORA2B; adenosine receptor A2b |  
 | K04268   | ADORA3; adenosine receptor A3 |  
 | K04269   | P2RY2; P2Y purinoceptor 2 |  
 | K04270   | P2RY1; P2Y purinoceptor 1 |  
 | K04271   | P2RY4; P2Y purinoceptor 4 |  
 | K04272   | P2RY6; P2Y purinoceptor 6 |  
 | K04273   | LPAR6, P2RY5; lysophosphatidic acid receptor 6 |  
 | K04274   | P2RY10; P2Y purinoceptor 10 |  
 | K04275   | LPAR4, GPR23; lysophosphatidic acid receptor 4 |  
 | K04276   | CXCR8, GPR35; C-X-C chemokine receptor type 8 |  
 | K04277   | CNR1; cannabinoid receptor 1 |  
 | K04278   | CNR2; cannabinoid receptor 2 |  
 | K04279   | PTAFR; platelet-activating factor receptor |  
 | K04280   | GNRHR; gonadotropin-releasing hormone receptor |  
 | K04282   | TRHR; thyrotropin-releasing hormone receptor |  
 | K04284   | GHSR; growth hormone secretagogue receptor |  
 | K04285   | MTNR1A; melatonin receptor type 1A |  
 | K04286   | MTNR1B; melatonin receptor type 1B |  
 | K04287   | GPR50; G protein-coupled receptor 50 |  
 | K04288   | S1PR1, EDG1, CD363; sphingosine 1-phosphate receptor 1 |  
 | K04289   | LPAR1, EDG2; lysophosphatidic acid receptor 1 |  
 | K04290   | S1PR3, EDG3; sphingosine 1-phosphate receptor 3 |  
 | K04291   | LPAR2, EDG4; lysophosphatidic acid receptor 2 |  
 | K04292   | S1PR2, EDG5; sphingosine 1-phosphate receptor 2 |  
 | K04293   | S1PR4, EDG6; sphingosine 1-phosphate receptor 4 |  
 | K04294   | LPAR3, EDG7; lysophosphatidic acid receptor 3 |  
 | K04295   | S1PR5, EDG8; sphingosine 1-phosphate receptor 5 |  
 | K04296   | LTB4R1; leukotriene B4 receptor 1 |  
 | K04297   | LTB4R2; leukotriene B4 receptor 2 |  
 | K04299   | P2RY14; P2Y purinoceptor 14 |  
 | K04303   | MAS1; proto-oncogene Mas |  
 | K04306   | RXFP1, LGR7; relaxin family peptide receptor 1 |  
 | K04307   | RXFP2, LGR8; relaxin family peptide receptor 2 |  
 | K04314   | PRLHR, GPR10; prolactin releasing hormone receptor |  
 | K04320   | MCHR1; melanin-concentrating hormone receptor 1 |  
 | K04322   | CYSLTR1; cysteinyl leukotriene receptor 1 |  
 | K04323   | CYSLTR2; cysteinyl leukotriene receptor 2 |  
 | K04332   | PTGDR; prostaglandin D2 receptor |  
 | K04576   | CALCR; calcitonin receptor |  
 | K04577   | CALCRL; calcitonin receptor-like |  
 | K04578   | CRHR1; corticotropin releasing hormone receptor 1 |  
 | K04579   | CRHR2; corticotropin releasing hormone receptor 2 |  
 | K04580   | GIPR; gastric inhibitory polypeptide receptor |  
 | K04581   | GLP1R; glucagon-like peptide 1 receptor |  
 | K04582   | GLP2R; glucagon-like peptide 2 receptor |  
 | K04583   | GCGR; glucagon receptor |  
 | K04584   | GHRHR; growth hormone releasing hormone receptor |  
 | K04585   | PTH1R, PTHR1; parathyroid hormone receptor 1 |  
 | K04586   | PTHR2; parathyroid hormone receptor 2 |  
 | K04587   | ADCYAP1R1, PACAPRI; pituitary adenylate cyclase-activating polypeptide type I receptor |  
 | K04588   | SCTR; secretin receptor |  
 | K04589   | VIPR1; vasoactive intestinal peptide receptor 1 |  
 | K04590   | VIPR2; vasoactive intestinal peptide receptor 2 |  
 | K04603   | GRM1; metabotropic glutamate receptor 1 |  
 | K04604   | GRM5; metabotropic glutamate receptor 5 |  
 | K04605   | GRM2; metabotropic glutamate receptor 2 |  
 | K04606   | GRM3; metabotropic glutamate receptor 3 |  
 | K04607   | GRM4; metabotropic glutamate receptor 4 |  
 | K04608   | GRM6; metabotropic glutamate receptor 6 |  
 | K04609   | GRM7; metabotropic glutamate receptor 7 |  
 | K04610   | GRM8; metabotropic glutamate receptor 8 |  
 | K04615   | GABBR; gamma-aminobutyric acid type B receptor |  
 | K04617   | GPR156, GABABL; gamma-aminobutyric acid type B receptor-like |  
 | K04803   | CHRNA1; nicotinic acetylcholine receptor alpha-1 |  
 | K04804   | CHRNA2; nicotinic acetylcholine receptor alpha-2 |  
 | K04805   | CHRNA3; nicotinic acetylcholine receptor alpha-3 |  
 | K04806   | CHRNA4; nicotinic acetylcholine receptor alpha-4 |  
 | K04807   | CHRNA5; nicotinic acetylcholine receptor alpha-5 |  
 | K04808   | CHRNA6; nicotinic acetylcholine receptor alpha-6 |  
 | K04809   | CHRNA7; nicotinic acetylcholine receptor alpha-7 |  
 | K04810   | CHRNA9; nicotinic acetylcholine receptor alpha-9 |  
 | K04811   | CHRNA10; nicotinic acetylcholine receptor alpha-10 |  
 | K04812   | CHRNB1; nicotinic acetylcholine receptor beta-1 |  
 | K04813   | CHRNB2; nicotinic acetylcholine receptor beta-2 |  
 | K04814   | CHRNB3; nicotinic acetylcholine receptor beta-3 |  
 | K04815   | CHRNB4; nicotinic acetylcholine receptor beta-4 |  
 | K04816   | CHRND; nicotinic acetylcholine receptor delta |  
 | K04817   | CHRNE; nicotinic acetylcholine receptor epsilon |  
 | K04818   | CHRNG; nicotinic acetylcholine receptor gamma |  
 | K05051   | TAAR; trace amine associated receptor |  
 | K05052   | NMUR1; neuromedin U receptor 1 |  
 | K05053   | NMUR2; neuromedin U receptor 2 |  
 | K05054   | MCHR2; melanin-concentrating hormone receptor 2 |  
 | K05062   | LEPR, CD295; leptin receptor |  
 | K05080   | GHR; growth hormone receptor |  
 | K05081   | PRLR; prolactin receptor |  
 | K05175   | GABRA; gamma-aminobutyric acid receptor subunit alpha |  
 | K05181   | GABRB; gamma-aminobutyric acid receptor subunit beta |  
 | K05184   | GABRD; gamma-aminobutyric acid receptor subunit delta |  
 | K05185   | GABRE; gamma-aminobutyric acid receptor subunit epsilon |  
 | K05186   | GABRG; gamma-aminobutyric acid receptor subunit gamma |  
 | K05189   | GABRP; gamma-aminobutyric acid receptor subunit pi |  
 | K05190   | GABRR; gamma-aminobutyric acid receptor subunit rho |  
 | K05192   | GABRQ; gamma-aminobutyric acid receptor subunit theta |  
 | K05193   | GLRA1; glycine receptor alpha-1 |  
 | K05194   | GLRA2; glycine receptor alpha-2 |  
 | K05195   | GLRA3; glycine receptor alpha-3 |  
 | K05196   | GLRB; glycine receptor beta |  
 | K05197   | GRIA1; glutamate receptor 1 |  
 | K05198   | GRIA2; glutamate receptor 2 |  
 | K05199   | GRIA3; glutamate receptor 3 |  
 | K05200   | GRIA4; glutamate receptor 4 |  
 | K05201   | GRIK1; glutamate receptor, ionotropic kainate 1 |  
 | K05202   | GRIK2; glutamate receptor, ionotropic kainate 2 |  
 | K05203   | GRIK3; glutamate receptor, ionotropic kainate 3 |  
 | K05204   | GRIK4; glutamate receptor, ionotropic kainate 4 |  
 | K05205   | GRIK5; glutamate receptor, ionotropic kainate 5 |  
 | K05206   | GRID1; glutamate receptor delta-1 subunit |  
 | K05207   | GRID2; glutamate receptor delta-2 subunit |  
 | K05208   | GRIN1; glutamate receptor ionotropic, NMDA 1 |  
 | K05209   | GRIN2A; glutamate receptor ionotropic, NMDA 2A |  
 | K05210   | GRIN2B; glutamate receptor ionotropic, NMDA 2B |  
 | K05211   | GRIN2C; glutamate receptor ionotropic, NMDA 2C |  
 | K05212   | GRIN2D; glutamate receptor ionotropic, NMDA 2D |  
 | K05213   | GRIN3A; glutamate receptor ionotropic, NMDA 3A |  
 | K05214   | GRIN3B; glutamate receptor ionotropic, NMDA 3B |  
 | K05215   | P2RX1; P2X purinoceptor 1 |  
 | K05216   | P2RX2; P2X purinoceptor 2 |  
 | K05217   | P2RX3; P2X purinoceptor 3 |  
 | K05218   | P2RX4; P2X purinoceptor 4 |  
 | K05219   | P2RX5; P2X purinoceptor 5 |  
 | K05220   | P2RX7; P2X purinoceptor 7 |  
 | K05221   | P2RX6, P2RXL1; P2X purinoceptor 6 |  
 | K05222   | TRPV1; transient receptor potential cation channel subfamily V member 1 |  
 | K05224   | GRP; gastrin-releasing peptide |  
 | K05228   | POMC; proopiomelanocortin |  
 | K05229   | PMCH; pro-melanin-concentrating hormone |  
 | K05234   | PPY; pancreatic polypeptide |  
 | K05242   | AVP; arginine vasopressin |  
 | K05243   | OXT; oxytocin-neurophysin 1 |  
 | K05246   | HCRT; hypocretin (orexin) neuropeptide |  
 | K05247   | NPFF; neuropeptide FF-amide peptide |  
 | K05250   | FSHB; follitropin subunit beta |  
 | K05251   | TSHB; thyrotropin subunit beta |  
 | K05252   | GNRH; gonadotropin-releasing hormone |  
 | K05253   | TRH; thyrotropin-releasing hormone |  
 | K05256   | CRH; corticotropin-releasing hormone |  
 | K05258   | GIP; gastric inhibitory polypeptide |  
 | K05260   | GHRH; growth hormone-releasing hormone |  
 | K05261   | PTH; parathyroid hormone |  
 | K05262   | ADCYAP; pituitary adenylate cyclase-activating polypeptide |  
 | K05264   | VIP; vasoactive intestinal peptide |  
 | K05267   | NPB; preproneuropeptide B |  
 | K05268   | NPBWR1; neuropeptides B/W receptor 1 |  
 | K05269   | PRH; prolactin-releasing peptide |  
 | K05547   | THRA, NR1A1; thyroid hormone receptor alpha |  
 | K05770   | TSPO, BZRP; translocator protein |  
 | K05771   | NR3C1, GR; glucocorticoid receptor |  
 | K05840   | DRD5; dopamine receptor D5 |  
 | K08039   | IAPP; islet amyloid polypeptide |  
 | K08362   | THRB, NR1A2; thyroid hormone receptor beta |  
 | K08375   | NPFFR2; neuropeptide FF receptor 2 |  
 | K08376   | NPSR1, GPR154; neuropeptide S receptor |  
 | K08377   | NPBWR2; neuropeptides B/W receptor 2 |  
 | K08378   | QRFPR, GPR103; pyroglutamylated RFamide peptide receptor |  
 | K08386   | P2RY8; P2Y purinoceptor 8 |  
 | K08387   | P2RY11; P2Y purinoceptor 11 |  
 | K08388   | P2RY13; P2Y purinoceptor 13 |  
 | K08397   | RXFP3, RLN3R1; relaxin family peptide receptor 3 |  
 | K08398   | RXFP4, RLN3R2; relaxin family peptide receptor 4 |  
 | K08521   | LHB; lutropin subunit beta |  
 | K08522   | CGA; glycoprotein hormones alpha chain |  
 | K09821   | AGT, SERPINA8; angiotensinogen |  
 | K15840   | PDYN, PENKB; proenkephalin B (prodynorphin) |  
 | K17278   | PGRMC1_2; membrane-associated progesterone receptor component |  
 | K23140   | KISS1; metastasis-suppressor KiSS-1 |  
 | K23143   | PTH2, TIP39; tuberoinfundibular peptide of 39 residues |  
 | K23681   | SLURP1; secreted Ly-6/uPAR-related protein 1 |  
 | K23682   | SLURP2; secreted Ly-6/uPAR-related protein 2 |  
 | K25355   | APELA; apelin receptor early endogenous ligand |  
 | K25367   | LYPD6; Ly-6/uPAR domain-containing protein 6 |  
 | K25368   | LYPD6B; Ly-6/uPAR domain-containing protein 6B |  
 | K25369   | LYNX1; Ly-6/neurotoxin-like protein 1 |  
 | K25370   | PATE; prostate and testis expressed protein |  
 | K25482   | GALP; galanin-like peptide |  
 | K25483   | GPHA2; glycoprotein hormone alpha-2 |  
 | K25484   | GPHB5; glycoprotein hormone beta-5 |  
 | K25692   | NPVF; pro-FMRFamide-related neuropeptide VF |  
 | K25693   | QRFP; orexigenic neuropeptide QRFP |  
 | K25695   | VGF; neurosecretory protein VGF |  
 | K26169   | PAQR6; membrane progestin receptor delta |  
 | K26170   | PAQR9; membrane progestin receptor epsilon |  
 | K26171   | TMEM97, S2R; sigma intracellular receptor 2 |  
 | K27951   | OGFR, OGFRL; opioid growth factor receptor |  
  |